The present invention relates to improvements in knife holder systems employing a reversible knife and counter-knife of the type which are housed in openings provided in wood chipping rotor heads, such as chipper discs.
The invention relates particularly to an improved knife holder of the character described in applicant's U.S. Pat. No. 5,820,042 issued Oct. 13, 1998, which I incorporate herein by reference.
The present improvement is likewise concerned with the utilization of low cost, disposable, reversible chipper knives clamped to a counter-knife which is secured within a knife holder assembly. It is particularly concerned with providing a structure and method which is capable of alterating the chip size without affecting the geometry of the hardware required to manufacture quality chips. In some industries, such as the pulp wood industry, it is necessary that the chips produced be of a consistent particular length and, also, of a predetermined thickness and width.
Prior art disposable knife systems have installed shims and/or plates between the underside of the tool holder and the mounting surface of the disc to elevate the tool holder and its related parts relative to the disc to seek to manufacture a predetermined size of chip. This is, for many reasons, not the best or most consistent way to manufacture a chip of predetermined size.